Polyethylene (PE) is a widely used material for packaging food. However, certain additives and their degradation products, which may be generated during transformation processes, may pose risks to consumers health if they migrate into food at levels exceeding safety thresholds. Therefore, identifying and quantifying these potential migrant compounds is crucial to ensuring consumer safety. In the present work, PE films and the raw materials used in their production were kindly provided by the industry to evaluate undesired compounds throughout the PE transformation chain. For that purpose, volatile and semi-volatile organic compounds were evaluated using gas chromatography coupled to mass spectrometry (GC-MS). Alkanes were identified as the most abundant compounds, along with antioxidants, lubricants, or Non-Intentionally Added Substances (NIAS), like 7,9-di-tert-butyl-1-oxaspiro(4,5)deca-6,9-diene-2,8-dione in the films. For the unidentified compounds, evaluations were conducted at various stages of the transformation chain, and migration assays were performed to assess their behavior.